Digestive disorder caused by gluten is common

A massive, multicenter study has found that celiac disease, a digestive disorder, is much more common in the United States than previously believed. The study, published in the Feb. 10 issue of the Archives of Internal Medicine, found that one out of every 133 Americans has celiac disease. Since only about one out of 4,700 Americans has been diagnosed, this means that 97 percent of cases in this country go undetected.

The prevalence is far higher for those considered at-risk. One out of 22 people with a diagnosed first-degree relative has the disease, one out of 39 with a diagnosed second-degree relative and one out of 56 people with symptoms but no diagnosed relative have the disease.

A digestive disorder, celiac disease is triggered by the protein gluten, which is found in wheat, barley and rye. In genetically susceptible people, gluten can trigger an autoimmune reaction in the intestines, which causes a variety of gastrointestinal symptoms and prevents the proper absorption of food and nutrients, leading to serious health consequences.

“We hope this study will change the perspective of the health care community and physicians will be more likely to test their patients for celiac disease,” said Alessio Fasano, the study’s principal investigator and professor of pediatrics, medicine and physiology at the University of Maryland School of Medicine.

“Undetected, untreated celiac disease is a recipe for trouble,” said Stefano Guandalini, Professor in Pediatrics and director of the University’s Celiac Disease Program.

“When this disease is diagnosed and treated early we can prevent complications,” said Guandalini, “but there is so little awareness of celiac disease in this country, even among physicians, that we often see people only after they develop severe problems. For a disease that can usually be treated effectively with a modified diet, that’s a horrible waste.”

Symptoms of celiac disease vary among individuals. Most common are diarrhea, constipation and abdominal pain, but “it can be a difficult disease to diagnose,” added Fasano, because symptoms also can include weight loss, anemia, osteoporosis, lassitude and depression. Sometimes, there are no symptoms.

“Equal recognition of celiac disease has been frustratingly slow to reach the United States,” said Guandalini, who trained in Italy. “In Europe, it typically takes a few weeks to go from the first symptoms to a diagnosis. In the United States, the average lag time between onset and diagnosis is 11 years.”

The study authors noted, “If physicians believe that CD is rare, they are less likely to test for it.” Third-party payers may compound that delay. In this study, insurance companies denied payment for an intestinal biopsy (to confirm the diagnosis) for 21 percent of the patients who had a positive blood test.

This study, the largest ever on the prevalence of celiac disease in the United States, took place over five years and included blood samples from 13,145 adults and children from 32 states.

Blood tests were performed for about 9,000 people considered “at-risk” because they had relatives with celiac disease, symptoms such as diarrhea, or other disorders associated with celiac disease, such as diabetes or anemia. Another 4,000 study participants without symptoms or affected relatives were considered “not at-risk.”

Celiac disease is an autoimmune disease, like type-1 diabetes or rheumatoid arthritis, and many scientists are beginning to suspect that it may “set the stage” for other autoimmune disorders, said Guandalini. “People who are diagnosed late or who continue to eat gluten have a higher prevalence of autoimmune diseases,” he added.

For someone to develop an autoimmune disease, explained Fasano, they must have a genetic predisposition and an environmental trigger. “Celiac disease is the only autoimmune disease where that trigger is known.”

The study supports the case for screening for celiac disease, which can be done through an $80 blood test.

“We are not ready to test the general population,” said Guandalini, “but there are literally millions of people at risk who need to be screened. We are ready for them.”